We report the growth of vertically aligned indium-doped ZnO (IZO) nanorods on a glass substrate using a low-temperature hydrothermal method. An IZO nanorod metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector (PD) was also fabricated. It was found that the UV-to-visible rejection ratio of the fabricated PD was ${\sim}{109}$ when biased at 1 V with a sharp cutoff at 390 nm. With an incident light wavelength of 390 nm and an applied bias of 1 V, it was found that measured responsivity of the PD was 2.5 A/W. Furthermore, it was also found that the noise equivalent power and detectivity of the fabricated IZO nanorod MSM PD were $1.42\times 10^{-10}~{\rm W}$ and $1.44\times 10^{11}~{\rm cm}\cdot{\rm Hz}^{0.5}\cdot{\rm W}^{-1}$, respectively.